diff options
Diffstat (limited to 'src/bfstd.c')
| -rw-r--r-- | src/bfstd.c | 92 |
1 files changed, 54 insertions, 38 deletions
diff --git a/src/bfstd.c b/src/bfstd.c index 6f39f54..97fa3b3 100644 --- a/src/bfstd.c +++ b/src/bfstd.c @@ -10,6 +10,7 @@ #include <fcntl.h> #include <langinfo.h> #include <nl_types.h> +#include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> @@ -575,7 +576,7 @@ size_t xstrwidth(const char *str) { } /** Get the length of the longest printable prefix of a string. */ -static size_t printable_len(const char *str, size_t len) { +static size_t printable_len(const char *str, size_t len, enum wesc_flags flags) { mbstate_t mb; memset(&mb, 0, sizeof(mb)); @@ -583,9 +584,23 @@ static size_t printable_len(const char *str, size_t len) { while (len > 0) { wchar_t wc; size_t mblen = mbrtowc(&wc, cur, len, &mb); - if (mblen == (size_t)-1 || mblen == (size_t)-2 || !iswprint(wc)) { + if (mblen == (size_t)-1 || mblen == (size_t)-2) { break; } + + bool safe = iswprint(wc); + + // Technically a literal newline is safe inside single quotes, + // but $'\n' is much nicer than ' + // ' + if (!(flags & WESC_SHELL) && iswspace(wc)) { + safe = true; + } + + if (!safe) { + break; + } + cur += mblen; len -= mblen; } @@ -623,13 +638,13 @@ static const char *dollar_esc(char c) { } /** $'Quote' a string for the shell. */ -static char *dollar_quote(char *dest, char *end, const char *str, size_t len) { +static char *dollar_quote(char *dest, char *end, const char *str, size_t len, enum wesc_flags flags) { static const char *hex[] = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F"}; dest = xstpecpy(dest, end, "$'"); while (len > 0) { - size_t plen = printable_len(str, len); + size_t plen = printable_len(str, len, flags); size_t elen = strcspn(str, "'\\"); size_t min = plen < elen ? plen : elen; dest = xstpencpy(dest, end, str, min); @@ -657,85 +672,86 @@ static char *dollar_quote(char *dest, char *end, const char *str, size_t len) { } /** How much of this string is safe as a bare word? */ -static size_t bare_len(const char *str) { +static size_t bare_len(const char *str, size_t len) { // https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_02 - return strcspn(str, "|&;<>()$`\\\"' *?[#˜=%!"); + size_t ret = strcspn(str, "|&;<>()$`\\\"' *?[#˜=%!"); + return ret < len ? ret : len; } /** How much of this string is safe to double-quote? */ -static size_t quotable_len(const char *str) { +static size_t quotable_len(const char *str, size_t len) { // https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_02_03 - return strcspn(str, "`$\\\"!"); + size_t ret = strcspn(str, "`$\\\"!"); + return ret < len ? ret : len; } /** "Quote" a string for the shell. */ -static char *double_quote(char *dest, char *end, const char *str) { +static char *double_quote(char *dest, char *end, const char *str, size_t len) { dest = xstpecpy(dest, end, "\""); - dest = xstpecpy(dest, end, str); + dest = xstpencpy(dest, end, str, len); return xstpecpy(dest, end, "\""); } /** 'Quote' a string for the shell. */ -static char *single_quote(char *dest, char *end, const char *str) { +static char *single_quote(char *dest, char *end, const char *str, size_t len) { bool open = false; - while (*str) { - size_t len = strcspn(str, "'"); - if (len > 0) { + while (len > 0) { + size_t chunk = strcspn(str, "'"); + chunk = chunk < len ? chunk : len; + if (chunk > 0) { if (!open) { dest = xstpecpy(dest, end, "'"); open = true; } - dest = xstpencpy(dest, end, str, len); - str += len; + dest = xstpencpy(dest, end, str, chunk); + str += chunk; + len -= chunk; } - while (*str == '\'') { + while (len > 0 && *str == '\'') { if (open) { dest = xstpecpy(dest, end, "'"); open = false; } dest = xstpecpy(dest, end, "\\'"); ++str; + --len; } } if (open) { dest = xstpecpy(dest, end, "'"); } + return dest; } -char *wordesc(const char *str) { - size_t len = strlen(str); +char *wordesc(char *dest, char *end, const char *str, enum wesc_flags flags) { + return wordnesc(dest, end, str, SIZE_MAX, flags); +} - // Worst case: every char is replaced with $'\xXX', so at most a 7x growth - size_t max_size = 7 * len + 3; - char *ret = malloc(max_size); - if (!ret) { - return NULL; - } - char *cur = ret; - char *end = ret + max_size; +char *wordnesc(char *dest, char *end, const char *str, size_t n, enum wesc_flags flags) { + size_t len = strnlen(str, n); + char *start = dest; - if (printable_len(str, len) < len) { + if (printable_len(str, len, flags) < len) { // String contains unprintable chars, use $'this\x7Fsyntax' - cur = dollar_quote(cur, end, str, len); - } else if (bare_len(str) == len) { + dest = dollar_quote(dest, end, str, len, flags); + } else if (!(flags & WESC_SHELL) || bare_len(str, len) == len) { // Whole string is safe as a bare word - cur = xstpecpy(cur, end, str); - } else if (quotable_len(str) == len) { + dest = xstpencpy(dest, end, str, len); + } else if (quotable_len(str, len) == len) { // Whole string is safe to double-quote - cur = double_quote(cur, end, str); + dest = double_quote(dest, end, str, len); } else { // Single-quote the whole string - cur = single_quote(cur, end, str); + dest = single_quote(dest, end, str, len); } - if (cur == ret) { - cur = xstpecpy(cur, end, "\"\""); + if (dest == start) { + dest = xstpecpy(dest, end, "\"\""); } - bfs_assert(cur != end, "Result truncated!"); - return ret; + return dest; } |